详解基于Spring Data的领域事件发布

// 实体定义
@Entity
public class Department implements Serializable {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Integer departmentId;

  @Enumerated(EnumType.STRING)
  private State state;
}

// 事件定义
public class DepartmentEvent {
  private Department department;
  private State state;
  public DepartmentEvent(Department department) {
    this.department = department;
    state = department.getState();
  }
}

// 领域服务
@Service
public class ApplicationService {

  @Autowired
  private ApplicationEventPublisher applicationEventPublisher;

  @Autowired
  private DepartmentRepository departmentRepository;

  @Transactional(rollbackFor = Exception.class)
  public void departmentAdd(Department department) {
    departmentRepository.save(department);
    // 事件发布
    applicationEventPublisher.publishEvent(new DepartmentEvent(department));
  }
}

// 实体定义
@Entity
public class SaleOrder implements Serializable {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Integer orderId;
  
  @Enumerated(EnumType.STRING)
  private State state;

  // 返回类型定义
  @DomainEvents
  public List<Object> domainEvents(){
    return Stream.of(new SaleOrderEvent(this)).collect(Collectors.toList());
  }

  // 事件发布后callback
  @AfterDomainEventPublication
  void callback() {
    System.err.println("ok");
  }
}

// 事件定义
public class SaleOrderEvent {
  private SaleOrder saleOrder;
  private State state;
  public SaleOrderEvent(SaleOrder saleOrder) {
    this.saleOrder = saleOrder;
    state = saleOrder.getState();
  }
}

// 领域服务
@Service
public class ApplicationService {
  @Autowired
  private OrderRepository orderRepository;
  
  @Transactional(rollbackFor = Exception.class)
  public void saleOrderAdd(SaleOrder saleOrder) {
    orderRepository.save(saleOrder);
  }
}

@Component
public class ApplicationEventProcessor {

  @EventListener(condition = "#departmentEvent.getState().toString() == 'SUCCEED'")
  public void departmentCreated(DepartmentEvent departmentEvent) {
    System.err.println("dept-event1:" + departmentEvent);
  }

  @Async
  @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT, condition = "#saleOrderEvent.getState().toString() == 'SUCCEED'")
  public void saleOrderCreated(SaleOrderEvent saleOrderEvent) {
    System.err.println("sale-event succeed1:" + saleOrderEvent);
  }

  @TransactionalEventListener(phase = TransactionPhase.BEFORE_COMMIT, condition = "#saleOrderEvent.getState().toString() == 'SUCCEED'")
  public void saleOrderCreatedBefore(SaleOrderEvent saleOrderEvent) {
    System.err.println("sale-event succeed2:" + saleOrderEvent);
  }

  @Async
  @TransactionalEventListener(phase = TransactionPhase.AFTER_ROLLBACK)
  public void saleOrderCreatedFailed(SaleOrderEvent saleOrderEvent) {
    System.out.println("sale-event failed:" + saleOrderEvent);
  }
}

@Transactional(rollbackFor = Exception.class)
public void departmentAdd(Department department) {
  departmentRepository.save(department);
  applicationEventPublisher.publishEvent(new DepartmentEvent(department));
  throw new RuntimeException("failed");
}

@Async
@TransactionalEventListener(phase = TransactionPhase.AFTER_ROLLBACK, condition = "#departmentEvent.getState().toString() == 'SUCCEED'")
public void departmentCreatedFailed(DepartmentEvent departmentEvent) {
  System.err.println("dept-event3:" + departmentEvent);
}